1. Field of the Invention
This invention relates generally to electrical connectors, and more specifically to the particular design of an electrical connector intended for use with high fidelity audio equipment whereby the sound quality of the system is markedly improved.
2. Discussion of the Prior Art
Until the present invention, there has not been an adequately designed connector for interfacing an audio system's components e.g., amplifier, speaker cable and speaker. The well-known banana plug, currently used in most amplifier and speaker systems is considered to be a "hand-me-down" from early radio and electronic instrumentation such as volt meters, oscilliscopes, etc. where the load impedances were generally in excess of 600 ohms and where the current encountered seldom exceeded a few milliamperes. The present day demands of high quality audio playback far exceed the capabilities of the banana plug as an acceptable connector.
By way of further explanation, present day high performance audio equipment commonly generate up to 80 volts of very complex, multifaceted waveforms, with 60 ampere peak currents not being uncommon. Rather than working into a 600 ohm impedance, high performance audio amplifiers generally interface with speakers exhibiting a 2 to 8 ohm load. The prior art banana plug generally comprises a plurality of thin, bowed tines of semi-tempered copper or brass plated with nickel (a relatively poor conductor). Thus, when mated in a cylindrical socket, the contact area between the bowed tines and the inner wall of the socket is quite small and subject to vibration. As the music or other audio programming material is passed through such a connector, the banana plug effectively becomes an active oscillator producing indiscriminate spectral energy variations.
Then too, the conventionally used banana plug is subject to oxidation and fatigue with continued use such that losses introduced by such a connector often vary from a few millivolts up to several volts. Frequency analysis of the noise produced by such faulty connectors shows that it is rich in frequency components well within the response characteristics of the human ear, typically anywhere from 150 Hz up to 5,000 Hz. This, of course, adversely effects the fidelity of the sound in that there is a drastic loss of definition and clarity. The vibrating tines of the banana plug, in effect, pulse amplitude modulates the audio signal delivered to the speaker load.
It is further found that banana plug type connectors of the prior art introduce up to a 35% loss. It is found to distort proper vowel structures and adds a graininess all its own to the amplified audio output. When analyzed with an oscilliscope connected directly across the banana plug as a large orchestral piece is being played, the noise components introduced by the vibration of the tines of the banana plug can be observed.
The defects encountered with banana plug-type electrical connectors may also be found in alternative arrangements commonly used for coupling the components of a high fidelity stereo sound system together. Fhanstock clips and the like are also seen to introduce losses and noise at a noticeable and objectionable level.